UIDocumentInteractionController unable to add ics file to calendar

Question

I am trying to open an ics (Calendar) file within my iOS application.

For debug purposes i have added a ics file to my bundle of a calendar eve

Answer 1

This may be irrelevant to your issue and probably explains nothing, but an employee was having an issue with his iPhone inconsistently accepting ICS calendar invites and was receiving "this invitation data is out of date" messages when it would not work. After multiple attempts of trial and error, the result was that if the iPhone was connected to wifi, it would give the "this invitation data is out of date" message. If it was connected only to the phone carrier network, it would successfully add the event.